This invention is directed to a method for making a deformable sealing element comprising an elastomeric material in which a spring is at least partially embedded.
In my U.S. Pat. No. 4,508,356, I have described and claimed a spring seal comprising an elastomeric jacket having a modified, C-shaped, interior cross-section and a metallic spring strip which conforms to and is registrable within a cavity of the jacket. I have also described in that patent other spring seals which constituted prior art at that time. The benefits of such a seal are well described in the aforecited U.S. Patant. However, making the spring seal requires a special approach to embedding the spring within an elastomeric or plastic material. More specifically, and with reference to FIGS. and 2 an internal cavity within the chosen elastomeric material must be first prepared.
As shown in FIG. 1 the jacket which will hold the spring must have an internal cavity of a predetermined size and shape.
As shown in FIG. 1 the jacket may be formed by an initial and final rotating forming tool having cutting knives and which extend at selected radial distances from the center of rotation of the tool. An initial cutting tool cuts along an initially solid body of Teflon or elastomer. The final tool is moved along the length of the jacket cutting a shape corresponding to the internal C-shaped cavity to be formed in the jacket. As the cutting tool cuts along the jacket material, the cutting edges of the knives remove material to leave the shaped, but unstressed sidearms of the jacket.
A convenient and advantageous spring and seal design is based upon a relatively complicated shape which is most difficult to cut. A more detailed explanation of the complexities is found in my above-mentioned U.S. patent.
With this complicated geometry, the shape of the spring and jacket can be precisely defined and appropriate tooling can be fabricated for any recess into which a spring is to be seated.
The elastomeric embedded spring has previously heretofore been difficult and expensive to make. The method of the present invention has greatly simplified the making of elastomeric embedded springs. The method allows for greater ease in manufacturing, so that larger numbers of the seals can be produced in less time and at substantially less cost. Yet, the quality of the seals is still high.
The features identified above as being desirable in the manufacture of elastomeric spring seals are all provided by the present invention.